The aim of this pretest for the CL-Experiment (CO2 long-term periodic injection experiment) was to find out how the temperature of two synthetic resins behave over time in a borehole.
For this resin pretest, double-walled cylinders (r1 = 2.15 cm, r2 = 2.5 cm, 17 cm high, 325.5 g) made of poly-amide were used and bedded on sand. The two resins and their corresponding hardener (Sikadur-52 and Biresin CR83 & CH83-10) were mixed at a ambient temperature of 10 °C. The resins poured from a height of 2.5 m through a plastic tube (diameter 5 mm) once in both annuli (1 L + 0.25 L) and once in the outer annulus (1 L) into the prepared forms (Figure 1). The temperature was measured with TMP35 sensors (Analog Devices, USA) attached to temperature-resistant silicone cable (wire size 0.25 mm2, Helukabel, Switzerland) (Figure 2). When both annuli have been filled, the temperature sensors were placed inside and outside respectively at a height of 9 cm. If only the outer annulus was filled, the temperature sensors were placed at a height of 6 (lower third) and 12 cm (higher third) respectively. The data logging was done every 6 seconds with a WioTerminal (Seeed Technology, China). The data logging and processing code was written with Arduino IDE (version 2.1.0). The data analysis was done with R (version 4.2.2) and RStudio (version 2023.03.0+386).